Onium-tagged Ru complexes as universal catalysts for olefin metathesis reactions in various media

Abstract

Polar olefin metathesis catalysts bearing a pendant electron-withdrawing (EWG) onium group are reviewed. The presence of this group not only activates the catalysts electronically, but renders them more hydrophilic. Catalysts can, therefore, be efficiently used not only in traditional media such as methylene chloride and toluene, but also in technical-grade alcohols, alcohol-water mixtures, and in neat water. In addition, some onium-tagged catalysts can act as inisurfs (initiator + surfactant molecules), promoting metathesis under heterogeneous aqueous conditions. Finally, some of these catalysts can be used in ionic liquids. Various ring-closing-, cross- and enyne metathesis reactions were conducted with these catalysts. © 2009 IUPAC.